Electric-motor-driven coal-cutter.



R. MARTIN. ELECTRIC MOTOR DRIVEN COAL CUTTER.

Patented July 6, 1915.

I APPLICATION FILED IAN- 2T I912- 3 SHEETS-SHEET l.

W/T/VESSES ATTO/P/VE x COLUMBIA PMNOGRAPH 60.. WASHINGTON, D. c.

R. MARTIN.

ELECTRIC MOTOR DRIVEN COAL CUTTER.

APPLICATION FILED mm]. 1912.

W/ T/VE 55155 ATTORNEY R. MARTIN.

EI.ECTRIC moroa DRIVEN COAL CUTTER.

} Patented July 6,1915.

APPLICATION FILED JAN-27v 1912.

' a SHEER-SHEET a.

M/VE/VTOF COLUMBIA PMNQOIIAPH c ROBERT MARTIN, 0F IRVINGTOIN NEW JERSEY.

ELECTRIC-MOTOR-DRIVEN COAL-CUTTER;

Specification of Letters Patent.

Patented July 6, 1915.

Application filed January 27, 1912. Serial No. 673,927.

To all 107mm it may concern Be it known that I, ROBERT MARTIN, a citizen of the United States, residing in the town of Irvington, in the county of Essex and State of New Jersey, have invented cer-, tain new and useful Improvements in Electric-Vlotor-Driven Coal-Cutters, of which the following is a full, clear, and exactdescription, such as will enable others skilled in the art to which it pertains to make, con struct, and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, formlng a part of this specification.

This invention relates to improvements in mining machinery, and more particularly to an electric motor driven coal cutter.

The object of this invention is to provide with a pick carrying rod, an armature rigidly secured to said'rod, means for reciprocating said rod and armature, an electromagnet and electro-responsive means for automatically operating said magnet, in order to disconnect the magnet from the armature which is secureclto the pick carrying rod to enable the said pick carrying rod to deliver the blow through its own momentum, and at a time when said rod is disconnected from the means which reciprocate the same.

A further object is to provide the armature holder and magnet with suitable aircushioning means, in order to regulate the cushioning effect when the magnet is about to attract the armature, thereby reducing the liability of the ends of the magnet from striking the armature a severe or sharp blow before the armature is attracted by the magnet.

A preferred construction of the lnvention is represented in the accompanying drawings, in which-,

Figure 1 represents a plan view of the.

wheels being broken away to more clearly illustrate the manner in which the handles are secured to the casing. Fig. 4."'repr esents a cross-section: taken on lines c -y of Fig. 1, looking in the direction'indicated by the arrow. enlarged plan view of the electro-magnet and armature, and illustrating the manner in which said armature is secured to thepick rod. Fig. 6 represents a fron'televation of the electro-magnet, looking in the direction indicated by the arrow'in Fig. 5 ;'and Fig. 7

represents a longitudinal section taken on lines az of Fig. 5, illustrating the manner:

inwhich the contact plates are carried by the casing.- j g Similarletters of'reference refer to like parts throughoutthe specification and draw-- -1ngS.f r

In the drawings, a represents preferably orr cn.

Fig. 5 represents an a wrought-iron casing in which are inclosed".

the various parts and which is providedjwith a cover I) on whichis located in anypconvenient manner, an electric motor 0. The shaft d of the motor 0 hasfixed thereto a gear 6 which drives a gear f fix'ed toa vertical shaft 9 which is mounted in a suitable a hearing it located on the motor 0.

The casing a isfurther provided with a tubular extension at projecting from the;

front of said casing andextending along the entire bottom length thereof. In this tubular extension a the pick or plunger rod '5 is located, to the front end of which is attached the pick j., The pick or plunger rod 71 has longitudinal sliding movement in thecasing a and slides insuitable bearings 71: located in the tubular extension a, and is prevented from turning, in its longitudinal reciprocatory movements by providing the plunger rod with feathers Z operating in grooves formed in the bearings is;

m represents wheels mounted upon 'trunnions n secured to the casingand 0 represent handles also secured to the casing near therearend thereof, by means of which the coal cutter can be held to its work and if desired, be moved from place to place. a V

. 79 represents anarmature holder, preferably made ofbronze, carrying'a wrought iron armature 1, said armature holder being provided with a dependinglug rgwwhich is fitted into a corresponding opening in the plunger rod 21 and is rigidly secured thereto in any convenient manner, as by'meansxof the pins 8.

t represents an electro-magnet of ordinary construction, to the front end of which is secured the supporting bracket 14 by means of bolts 1).

w represents a connecting rod, the rear end of which is pivotally connected to the gear 7 by means of the stud b and the front end of which is similarly connected to the bracket 10 by means of the stud 0. Secured in any convenient manner to the longitudinal sides of the electro-magnet t are the gibs d, preferably by means of the bolts 6, said gibs having sliding engagement with the slides 7 which are secured to the inside of the casing a.

9' represent fiber supports which are secured to the electro-magnet 25 in any convenient manner, and in which are located spring-pressed carbon contacts 71, electrically connected with the electro-magnet, the exposed ends of which have sliding engagement with the copper contacts 2" which are inserted in the fiber blocks 7", said fiber blccks being secured to the supports 70, said supports being conveniently secured in any well known manner to the under side of the cover 5.

In order to provide suitable air-cushioning means between the end of the magnet t and the armature holder p, thereby reducing the liability of the ends of the magnet from striking the armature a severe or sharp blow, I provide the armature holder 7) with bushings n, so arranged that the inside diameters thereof, together with the face of the armature form dash-pots for the reception of the ends of the magnet, and further provide in the ends of said magnets, air-ducts Z, said ducts being provided with adjusting screws m, in order to regulate the cushioning effect when the magnet is about to attract the armature. By means of these ducts, the air from Within the bushings is forced out, thereby providing a suitable cushioning effect for the magnet.

0 rep esents a spiral spring and 79 a disk conveniently located in any well-known manner in the rear end of the tubular extension a, designed to impart a cushioning effect upon the pick rod should the end thereof strike said disk.

In operation, as the gears e and f are rotated by the motor, the pick rod or plunger i will be reciprocated. Supposing the parts to be in the position shown in Figs. 1 and 2 of the drawings, the magnet t contacting with the armature Q and the carbon contacts h at the end of the contact plates 2', with the pick or plunger rod 2' at one half the limit of its outward movement, any further revolution of the gear 7 in the directlon lndlcated by the arrow, will break the electrical connection between the electromagnet t and the armature g, for the reason that any further movement of the connecting rod 10 with its attached magnet, will cause the circuit to be broken at the point where the carbon contacts it become disengaged from the copper contact plates 2', as clearly seen in Figs. 2 and 7 of the drawings, and permit the pick carrying rod or plunger 71, to the front end of which is attached the pick j, to deliver the blow by its own momentum.

It is to be understood that when the foregoing operation takes place, the pick is in the position shown in the drawings, namely, in engagement with the coal or in very close proximity thereto, and should it happen that the pick contacts with a very hard material, such as a sulphur ball for instance, the same will deliver its effective blow and rebound, striking the disk 79, thereby compressing the spring 0 which will force the pick carrying rod forward until the armature g attached thereto again makes electrical connection with the magnet, when the operatlon is repeated, thus obviating any possibility of disturbing the operating mechanism of the device.

Experience has demonstrated that the organization above described, is a highly eiiicient one, and while the device described is the preferred embodiment of my present invention, I do not care to restrict myself to the exact details of construction, combination, and arrangement herein set forth, it being obvious that minor variations thereof not involving the exercise of invention may be made by any skilled mechanic, and such departures from what is herein described and claimed not involving invention, I consider as within the scope and terms of my claim.

I claim:

In a machine of the character described, a casing, a pick-carrying rod located within said casing, an armature holder provided with an armature carried by said rod, a connecting rod, an electro-magnet pivotally connected to said connecting rod and engaging said armature, air-cushioning means located in the ends of said magnet and in the armature holder, and a make-and-break connection secured to the casing and to the electromagnet, whereby said pick-carrying rod is disconnected from the connecting rod.

This specification signed and witnessed this 24th day of January, 1912.

ROBERT MARTIN.

Witnesses FREDK C. FISCHER, CLIFFORD A. ALLIs'roN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

